Mirrormere Guardian

When Mirrormere Guardian dies, the Ring tempts you.

Heart's Desire

Create a 1/1 white Human creature token. (Then exile this card. You may cast the creature later from exile.)

Lovestruck Beast

Lovestruck Beast can't attack unless you control a 1/1 creature.

Lovestruck Beast // Heart's Desire

Slip On the Ring

Exile target creature you own, then return it to the battlefield under your control. The Ring tempts you.

Frodo Baggins

Whenever Frodo Baggins or another legendary creature you control enters, the Ring tempts you.
As long as Frodo is your Ring-bearer, it must be blocked if able.

Shortcut to Mushrooms

When Shortcut to Mushrooms enters, the Ring tempts you.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on target creature you control.

Stalwarts of Osgiliath

When Stalwarts of Osgiliath enters, the Ring tempts you.
Whenever you draw your second card each turn, put a +1/+1 counter on Stalwarts of Osgiliath.

Plains

Scoured Barrens

Scoured Barrens enters tapped.
When Scoured Barrens enters, you gain 1 life.
{T}: Add {W} or {B}.

Blossoming Sands

Blossoming Sands enters tapped.
When Blossoming Sands enters, you gain 1 life.
{T}: Add {G} or {W}.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Bag End Porter

Whenever Bag End Porter attacks, it gets +X/+X until end of turn, where X is the number of legendary creatures you control.

Mirkwood Spider

Deathtouch
Whenever Mirkwood Spider attacks, target legendary creature you control gains deathtouch until end of turn.

Fog on the Barrow-Downs

Enchant creature
Enchanted creature is a Spirit and can't attack or block. (It loses all other creature types.)

Old Man Willow

Old Man Willow's power and toughness are each equal to the number of lands you control.
Whenever Old Man Willow attacks, you may sacrifice another creature or a token. When you do, target creature an opponent controls gets -2/-2 until end of turn.

Bill the Pony

When Bill the Pony enters, create two Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Sacrifice a Food: Until end of turn, target creature you control assigns combat damage equal to its toughness rather than its power.

Swamp

Wose Pathfinder

{T}: Add one mana of any color.
{6}{G}, {T}: Another target creature gets +3/+3 and gains trample until end of turn.

Butterbur, Bree Innkeeper

At the beginning of your end step, if you don't control a Food, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Faramir, Field Commander

At the beginning of your end step, if a creature died under your control this turn, draw a card.
Whenever the Ring tempts you, if you chose a creature other than Faramir, Field Commander as your Ring-bearer, create a 1/1 white Human Soldier creature token.

Forest

Quickbeam, Upstart Ent

Whenever Quickbeam, Upstart Ent or another Treefolk you control enters, up to two target creatures each get +2/+2 and gain trample until end of turn.

Enraged Huorn

Trample
When Enraged Huorn enters, the Ring tempts you.

Banish from Edoras

This spell costs {2} less to cast if it targets a tapped creature.
Exile target creature.

Jungle Hollow

Jungle Hollow enters tapped.
When Jungle Hollow enters, you gain 1 life.
{T}: Add {B} or {G}.

Meriadoc Brandybuck

Whenever one or more Halflings you control attack a player, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")